Agilent Technologies 5975C TAD VL MSD, Troubleshooting And Maintenance Manual

Page: 172 / 276

172 5975 Series MSD Troubleshooting and Maintenance Manual
6
Vacuum System
Overview
The vacuum system creates the high vacuum (low pressure) required for the
MSD to operate. Without the vacuum, the molecular mean free path would be
very short and ions would collide with air molecules before they could reach
the detector. peration at high pressures also would damage analyzer
components.
The 5975 Series MSDs use two vacuum pumps to obtain the vacuum levels
needed. One of two foreline pumps (standard or dry) creates a low vacuum,
then a high vacuum pump engages to create the vacuum needed for operation.
The 5975 Series MSD uses one of three kinds of high vacuum pumps: a
diffusion pump or one of two turbomolecular (turbo) pumps. The pump type
determines the maximum column flow supported by the MSD. See
Table 9 .
Most vacuum system operation is automated. Operator interaction is through
the data system or control panel. Monitor the vacuum system through the data
system and/or local control panel.
Table 9 Recommended maximum flow rates per high vacuum pump
Model number Description Maximum recommended
column flow
G3170A
G3175A Diffusion pump, EI 1.5 mL/min
G3171A
G3176A Standard turbo pump, EI 2.0 mL/min
G3172A Performance turbo pump, EI 4.0 mL/min
G3174A Performance turbo pump, EI, PCI, NCI 4.0 mL/min